Signal from fire alarm vs. breaking power directly at doors. Code ref help please!!

[PatrickS]

Morning all, post inspired by this article http://idighardware.com/2010/12/nfpa-72-on-access-control-2/ which linked back to this forum in the comments.

Let's say I have a ten story building with an access control system wired to stairwell exits which have crashbars and a power supply above the door. I cannot find where it would be mandatory to provide fire alarm relays directly connected to these power supplies vs. providing the access control system a single relay to give an unlock signal from the fire command room. All I can see is required is to provide two relays, one for general alarm (or one per floor if doing floor above/floor below) and one for keyswitch operation from the the fire command room to give the access control system the signal.

All help/insights greatly appreciated!

 

[LGreene]

Hi Patrick -

Sorry for the late reply - I didn't see this until now. I wrote that article, and I have never seen anything in a code or standard specific to the fire alarm relays.

- Lori

 

[departSure Dave]

Patrick -
Did you find an answer to your inquiry? If so, can you post what you found.
I reviewed Lori's article and read a few pieces describing the requirements of NFPA 72.
If the individual power supplies at each door are all fed by power from one source - and they don't have battery backup - then your suggested single relay should be acceptable since all the access controlled doors would be released by dropping out that 1 relay. (NFPA 72 – 2010, paragraph 21.9.4)
However, if the power supplies at each door have battery backup to keep the doors locked in the event of a power loss, then an alarm relay at each UL294 listed power supply is likely required per NFPA 72 – 2010, paragraph 21.9.3
I'm not an expert, but this is my interpretation.
David

 

[departSure Dave]

Patrick -
I just read another article which you can find here: http://goo.gl/otgWm2
In this article is this paragraph, which may apply:

The connections to all emergency control functions also require specific attention. For example, the contractor must locate a listed relay or other listed appliance connected to the FAS used to initiate control of protected premises emergency control functions within 3 feet of the controlled circuit or appliance. The wiring interconnection between the FAS and controlled electrical and mechanical systems must comply with the requirements of NFPA 70-2008, The National Electrical Code. And, the FAS must monitor the integrity of the interconnected wiring.

 

[cda]

Welcome Dave !!!

Do you mind saying what you do for a paycheck

 

[departSure Dave]

cda,
I'm in the door hardware industry.
I've served as a product engineer and product manager over the past 20 years for some known door hardware manufacturers.
I'm a professional engineer (mechanical) and FDAI fire door inspector.
My current role is a fire door inspector in the healthcare industry, where the LSC (NFPA 101 -2012) has recently been adopted by CMS.
I frequent this forum for the past 2-3 years and know you are a frequent contributor - both here and on Lori's blog (which I also frequent).
David

 

[cda]

Fantastic , some great knowledge to bring to this site!!!

We recruited another one from Lori

 

[PatrickS]

Patrick -
Did you find an answer to your inquiry? If so, can you post what you found.
I reviewed Lori's article and read a few pieces describing the requirements of NFPA 72....
David

Sorry for the delay getting back with you, for some reason I never got notified that anyone had answered! Agreed on both points if I was required to cut power, which I still am not convinced I am. I think the question becomes murky as I cannot find anything saying "how" the interaction has to be accomplished.

Heavily paraphrasing 72 21.9-21.9.6, if there is a device or system which locks egress doors it shall be connected to the fire alarm system. It shall unlock on fire alarm signal, and not re-lock until the fire alarm signal is cleared.

1. It only mentions that it has to happen, not how it has to happen
2. Tangent here, bu I'm also confused on the lock terminology, i.e. is a stairwell door with crashbar "locked" in the egress path if it is only controlling entry to the floor from the stairwell?

Problem #1: Floor of incident/above/below fire alarm. The above tells me that during a fire electronically locked doors in path of egress (stairwell doors in in this instance) shall unlock in the direction of egress, and this shall happen "as prescribed by other laws, codes, and governing standards". I cannot see where it would not be permissible/acceptable for fire alarm to provide ten relays, one next to the access control system on each floor which they would land on an input and program that floors stairwell doors to unlock on state change. This is assuming the access control system on each floor is "smart" and can accept inputs on each floor. Could also be accomplished with ten relays in the main access control location. I also cannot find anything telling me I have to accomplish this in any other way. Murky!

Problem #2: Code requires a keyswitch, the intent of of which I'm assuming is to let Firefighters have access to any floor in the stairwell without having to badge in or swipe a card. I cannot see where it would not be permissible/acceptable for fire alarm to provide one relay next to the access control system which they would land on an input and program all stairwell doors to unlock on state change. I also cannot find anything telling me I have to accomplish this in any other way. Murky!

I appreciate any responses. Just frustrated, but if this stuff was easy we wouldn't have all these cool jobs right?

 

[PatrickS]

Hi Patrick -

Sorry for the late reply - I didn't see this until now. I wrote that article, and I have never seen anything in a code or standard specific to the fire alarm relays.

- Lori

Thanks Lori! Fleshed it out a bit more in response to David's reply, maybe that helps?

 

[LGreene]

• Tangent here, but I'm also confused on the lock terminology, i.e. is a stairwell door with crashbar "locked" in the egress path if it is only controlling entry to the floor from the stairwell?

The stairway door section of the IBC (1010.1.9.11 in the 2015 edition) addresses the locked hardware on the stair side of the door. The hardware on the egress side of the stair door, leading into the stairwell, almost always provides free egress into the stair (with the exception of delayed egress, controlled egress, and detention/correctional applications). The remote unlocking via the fire alarm or fire command center applies to the stair side, so you could have fire exit hardware or a lockset that would allow free egress into the stairwell, and the lever on the stair side would be electrified so it could be unlocked remotely as required by the section on stairway doors.